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Normanbya normanbyi (W. Hill) L. H. Bailey (Arecaceae) is a monoecious, arborescent palm with a very small distribution area within the Daintree rainforest in north-eastern Australia. Our 2-year study was focused on the reproductive phenology at the individual and population level. At the population level flowering peaked in the dry season, whereas fruiting was confined to the wet season. Each palm can bear up to three inflorescences/infructescences at the same time. Flowering of each inflorescence is separated from each other by a couple of weeks. A single inflorescence consists of about 1900 staminate and 800 pistillate flowers. The flowering of N. normanbyi is protandrous with a staminate phase lasting 40 days and a pistillate phase of approximately 2 weeks. Between both phases is a non-flowering phase of about 9 days. Fruit ripening takes 21 weeks, with an average of about 280 ripe fruit per tree. Comparison of three study plots revealed a moderate synchrony of flowering and fruiting initiation in this species of palm. The male phase of flowering shows a higher degree of synchrony than the female phase at the population level. Seasonal regularity of flowering and fruiting peaks appears to be predictable. The general flowering and fruiting phenology of N. normanbyi follows a subannual pattern with a strong tendency towards a continual pattern.

A new species of gall midge, Normanbyomyia fructivora gen. & sp. n., was found infesting flowers and fruit of the black palm, Normanbya normanbyi (Arecaceae), in the tropical forest of north-eastern Australia. Larvae of the gall midge live between the perianth and the young fruit causing abnormal fruit growth. Infested fruit are substantially smaller than healthy ones, fall off prematurely and decay on the ground without producing seedlings. Normanbyomyia, a new genus erected for the new species is placed within the supertribe Lasiopteridi and is characterised by a conspicuous female abdominal segment 8 that is inflated and strongly sclerotised, and wide male parameres that loosely sheath the aedeagus and bear no papillae. A key to Australian Lasiopteridi is provided. The new species becomes the first described gall midge that feeds on a plant from the palm family, Arecaceae.